1. Field
One or more embodiments of the present invention relates to splatting, and more particularly, to a point-based apparatus, method and medium for performing rendering of a point model by generating a spherical (or hemi-spherical) splat on each point on which the point model is projected.
2. Description of the Related Art
Rendering of image data generally denotes visualization of the image data.
To render a point model comprising a combination of points and having a 3D shape, a point-based rendering algorithm is used to generate a planar splat such as a square or sphere on each of the points on which the point model is projected, and a polygon-based rendering algorithm is used to appropriately combine a plurality of polygons.
The polygon-based rendering algorithm takes a long time to generate and combine the plurality of polygons. Therefore, if the point model has a large quantity of data or a complex shape, the number of operations for generating and combining the plurality of polygons is increased, which reduces rendering speed.
According to the point-based rendering algorithm, the points on which the point model are projected are arranged closer to a point of view, and planar splats such as a square or circle are generated according to the arrangement of the points. Therefore, pixel information of a splat, which overlaps with another splat, is lost. In this case, a scale effect occurs such that the splats look like scales. The scale effect deteriorates the appearance of the rendered point model. Furthermore, according to the point-based rendering algorithm, when the point of view moves, the points are rearranged and the pixel information of the splat is changed due to lost pixel information. Therefore, image quality of the rendered point model can be greatly deteriorated because of the changing point of view.
FIGS. 1A and 1B are diagrams for explaining problems of the point-based rendering algorithm. Referring to FIG. 1A, (a) shows points (110, 112, 114) on which the point model is projected, (b) shows square splats (120, 122, 124), and (c) shows spherical splats (130, 132, 134). The plane splat 120 (or 130) is a splat of the point 110. The plane splat 122 (or 132) is a splat of the point 112. The plane splat 124 (or 134) is a splat of the point 114. According to the point-based rendering algorithm, pixel information of the splat 122 (or 132) that overlaps another splat 124 (or 134) is lost and the appearance of a rendered point mode is deteriorated as illustrated in FIG. 1A (b) and (c).
Referring to FIG. 1B, at a point of view 140, a splat 134 does not overlap other splats, and pixel information on an upper part of splats 130 and 132 are lost. At a point of view 142, a splat 132 does not overlap other splats, and pixel information on an upper part of a splat 130 and on a lower part of a splat 134 are lost. At a point of view 144, a splat 130 does not overlap other splats, and pixel information on lower parts of splats 132 and 134 are lost. Therefore, image quality of the rendered point model varies according to points of view.